Lepidoptera feed-dependent on birch in air-polluted area
Biologia (Bratislava) 54(2): 151-157
In an air-polluted area (>60 micro g m-3 sulfur dioxide per year) in North Bohemia (Czech Republic) with dominant birch (Betula verrucosa) [B. pendula] stands, the lepidopteran fauna was evaluated based on collections by light traps, shaking onto a sheet and soil photoeclectors at 6 sites. One hundred and eighty five species were found to be feed-dependent on birch, however, the birch stands established in air-polluted sites were endangered by a small group of phytophagous Lepidoptera. Of 22 species with larvae hibernating in soil, Orthotaenia undulana (36.9%), Psyche casta (7.6%) and Eriocrania spp. were most numerous. Cabera pusaria (34.7%), Operophtera fagata (16.4%) and Coleophora serratella (7.8%) were the most important pests out of the 119 species with larvae developing in tree crowns. Despite the different site conditions, no significant deviations were found in the crown fauna of the individual study sites. Among the 123 lepidopteran species caught by light traps, the most numerous were Biston betularia (7.7%), Cabera pusaria (7.0%), Apotomis betuletana (6.9%) and Pandemis cerasana (6.2%). The results indicated that Cabera pusaria, Coleophora serratella, Eriocrania sp., B. betularia, Operophtera fagata and Orthotaenia undulana are significant birch-feeding Lepidoptera, with increasing population densities. The most harmful species appear in early spring (Eriocrania sp., Coleophora serratella, Operophtera fagata), while only Cabera pusaria is economically important in late summer.